| 1. |
- Aad, G., et al.
(författare)
-
Readiness of the ATLAS Tile Calorimeter for LHC collisions
- 2010
-
Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 70:4, s. 1193-1236
-
Tidskriftsartikel (refereegranskat)abstract
- The Tile hadronic calorimeter of the ATLAS detector has undergone extensive testing in the experimental hall since its installation in late 2005. The readout, control and calibration systems have been fully operational since 2007 and the detector has successfully collected data from the LHC single beams in 2008 and first collisions in 2009. This paper gives an overview of the Tile Calorimeter performance as measured using random triggers, calibration data, data from cosmic ray muons and single beam data. The detector operation status, noise characteristics and performance of the calibration systems are presented, as well as the validation of the timing and energy calibration carried out with minimum ionising cosmic ray muons data. The calibration systems' precision is well below the design value of 1%. The determination of the global energy scale was performed with an uncertainty of 4%.
|
|
| 2. |
- Aad, G., et al.
(författare)
-
Studies of the performance of the ATLAS detector using cosmic-ray muons
- 2011
-
Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 71:3
-
Tidskriftsartikel (refereegranskat)abstract
- Muons from cosmic-ray interactions in the atmosphere provide a high-statistics source of particles that can be used to study the performance and calibration of the ATLAS detector. Cosmic-ray muons can penetrate to the cavern and deposit energy in all detector subsystems. Such events have played an important role in the commissioning of the detector since the start of the installation phase in 2005 and were particularly important for understanding the detector performance in the time prior to the arrival of the first LHC beams. Global cosmic-ray runs were undertaken in both 2008 and 2009 and these data have been used through to the early phases of collision data-taking as a tool for calibration, alignment and detector monitoring. These large datasets have also been used for detector performance studies, including investigations that rely on the combined performance of different subsystems. This paper presents the results of performance studies related to combined tracking, lepton identification and the reconstruction of jets and missing transverse energy. Results are compared to expectations based on a cosmic-ray event generator and a full simulation of the detector response.
|
|
| 3. |
- Aad, G., et al.
(författare)
-
The ATLAS Inner Detector commissioning and calibration
- 2010
-
Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 70:3, s. 787-821
-
Tidskriftsartikel (refereegranskat)abstract
- The ATLAS Inner Detector is a composite tracking system consisting of silicon pixels, silicon strips and straw tubes in a 2 T magnetic field. Its installation was completed in August 2008 and the detector took part in data-taking with single LHC beams and cosmic rays. The initial detector operation, hardware commissioning and in-situ calibrations are described. Tracking performance has been measured with 7.6 million cosmic-ray events, collected using a tracking trigger and reconstructed with modular pattern-recognition and fitting software. The intrinsic hit efficiency and tracking trigger efficiencies are close to 100%. Lorentz angle measurements for both electrons and holes, specific energy-loss calibration and transition radiation turn-on measurements have been performed. Different alignment techniques have been used to reconstruct the detector geometry. After the initial alignment, a transverse impact parameter resolution of 22.1 +/- 0.9 mu m and a relative momentum resolution sigma (p) /p=(4.83 +/- 0.16)x10(-4) GeV(-1)xp (T) have been measured for high momentum tracks.
|
|
| 4. |
- Aad, G., et al.
(författare)
-
The ATLAS Simulation Infrastructure
- 2010
-
Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 70:3, s. 823-874
-
Tidskriftsartikel (refereegranskat)abstract
- The simulation software for the ATLAS Experiment at the Large Hadron Collider is being used for large-scale production of events on the LHC Computing Grid. This simulation requires many components, from the generators that simulate particle collisions, through packages simulating the response of the various detectors and triggers. All of these components come together under the ATLAS simulation infrastructure. In this paper, that infrastructure is discussed, including that supporting the detector description, interfacing the event generation, and combining the GEANT4 simulation of the response of the individual detectors. Also described are the tools allowing the software validation, performance testing, and the validation of the simulated output against known physics processes.
|
|
| 5. |
- Aad, G., et al.
(författare)
-
Commissioning of the ATLAS Muon Spectrometer with cosmic rays
- 2010
-
Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 70:3, s. 875-916
-
Tidskriftsartikel (refereegranskat)abstract
- The ATLAS detector at the Large Hadron Collider has collected several hundred million cosmic ray events during 2008 and 2009. These data were used to commission the Muon Spectrometer and to study the performance of the trigger and tracking chambers, their alignment, the detector control system, the data acquisition and the analysis programs. We present the performance in the relevant parameters that determine the quality of the muon measurement. We discuss the single element efficiency, resolution and noise rates, the calibration method of the detector response and of the alignment system, the track reconstruction efficiency and the momentum measurement. The results show that the detector is close to the design performance and that the Muon Spectrometer is ready to detect muons produced in high energy proton-proton collisions.
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
| 11. |
|
|
| 12. |
|
|
| 13. |
|
|
| 14. |
|
|
| 15. |
|
|
| 16. |
|
|
| 17. |
|
|
| 18. |
|
|
| 19. |
|
|
| 20. |
|
|
| 21. |
|
|
| 22. |
|
|
| 23. |
|
|
| 24. |
|
|
| 25. |
|
|
| 26. |
|
|
| 27. |
- Chen, Jiajia, et al.
(författare)
-
Enhancing IPACT with limited service for multi-thread DBA in long-reach EPON
- 2010
-
Ingår i: Communications and Photonics Conference and Exhibition (ACP), 2010 Asia. - 9781424471119 ; , s. 629-630
-
Konferensbidrag (refereegranskat)abstract
- In this paper we propose an enhanced IPACT with limited service for multi-thread DBA in long-reach EPON. We evaluate our scheme by simulations in single-thread and double-thread cases and show that the DBA performance in terms of average delay and jitter can be significantly improved by the proposed algorithm.
|
|
| 28. |
- De Andrade, Marilet, et al.
(författare)
-
Enhanced IPACT : solving the over-granting problem in long-reach EPON
- 2013
-
Ingår i: Telecommunications Systems. - : Springer Science and Business Media LLC. - 1018-4864 .- 1572-9451. ; 54:2, s. 137-146
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper we address an issue referred to as "over-granting problem", which is inherent in the existing dynamic bandwidth allocation algorithms for Ethernet-based Passive Optical Networks (EPON), in particular when deployed for multi-threaded scheme in long-reach scenario. In order to solve this problem we design a scheme for the algorithm of Interleaved Polling with Adapted Cycle Time (IPACT) with the limited service discipline. We evaluate the proposed scheme through simulations for single-thread and double-thread cases and demonstrate that, the network performance can be significantly improved by our solution in terms of average delay, jitter, and throughput.
|
|
| 29. |
- Fiorani, Matteo, et al.
(författare)
-
Challenges for 5G transport networks
- 2014
-
Ingår i: 2014 IEEE International Conference on Advanced Networks and Telecommunication Systems, ANTS 2014. - : IEEE conference proceedings. - 9781479958689
-
Konferensbidrag (refereegranskat)abstract
- 5G mobile communications is seen as the enabler for the networked society where connectivity will be available anywhere and anytime to anyone and anything. The details of 5G are the subject to ongoing research and debate, mostly focused on understanding radio technologies that can enable the 5G vision. So far, less work has been dedicated to the challenges that 5G will pose to the transport network. This paper provides a first analysis of the key challenges to 5G transport in terms of capacity, flexibility and costs, for example. Different use cases are discussed as well as technology options and control plane concepts.
|
|
| 30. |
- Fiorani, Matteo, et al.
(författare)
-
Modeling energy performance of C-RAN with optical transport in 5G network scenarios
- 2016
-
Ingår i: Journal of Optical Communications and Networking. - : IEEE. - 1943-0620 .- 1943-0639. ; 8:11
-
Tidskriftsartikel (refereegranskat)abstract
- The deployment of new 5G wireless interfaces based on massive multiantenna transmission and beamforming is expected to have a significant impact on the complexity and power consumption of the transport network. This paper analyzes the energy performance of four radio access network (RAN) architectures, each one utilizing a different option for splitting the baseband processing functions. The radio segment is based on Long-Term Evolution (LTE) and 5G radio access technologies. The transport segment is based on optical wavelength division multiplexing, where coherent and direct detection transmissions are considered. The energy consumption of each RAN architecture is weighted against i) the benefits for the radio segment as a function of the level of centralization of the baseband processing functions and ii) the power consumption levels needed to accommodate the capacity generated at each base station. Results show that, with LTE radio interfaces, the energy consumption of the transport network amounts to only a few percent of the overall network power consumption. As a result, fully centralized LTE radio architectures are a viable option, with energy savings of at least 27% compared with conventional distributed architectures. On the other hand, with advanced 5G radio interfaces, centralized architectures, if not carefully designed, might become impractical due to the excessive energy consumption of the transport network (i.e., as a result of the huge capacity to be accommodated). This aspect can be mitigated via a careful joint design of the radio and the transport network (i.e., leveraging on appropriate optical transmission techniques and compromising where needed on the radio network performance).
|
|
| 31. |
|
|
| 32. |
- Hellsvik, Johan, et al.
(författare)
-
Dynamics of diluted magnetic semiconductors from atomistic spin-dynamics simulations : Mn-doped GaAs
- 2008
-
Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 78:14, s. 144419-
-
Tidskriftsartikel (refereegranskat)abstract
- The dynamical behavior of the magnetism of diluted magnetic semiconductors (DMSs) has been investigated by means of atomistic spin-dynamics simulations. The conclusions drawn from the study are argued to be general for DMS systems in the low-concentration limit, although all simulations are done for 5% Mn-doped GaAs with various concentrations of As antisite defects. The magnetization curve M(T) and the Curie temperature T-C have been calculated and are found to be in good correspondence to the results from Monte Carlo simulations and experiments. Furthermore, equilibrium and nonequilibrium behaviors of the magnetic pair-correlation function have been extracted. The dynamics of DMS systems reveals a substantial short-ranged magnetic order even at temperatures at or above the ordering temperature, with a nonvanishing pair-correlation function extending up to several atomic shells. For the high As antisite concentrations the simulations show a short-ranged antiferromagnetic coupling and a weakened long-ranged ferromagnetic coupling. For sufficiently large concentrations we do not observe any long-ranged ferromagnetic correlation. A typical dynamical response shows that starting from a random orientation of moments, the spin correlation develops very fast (similar to 1 ps) extending up to 15 atomic shells. Above similar to 10 ps in the simulations, the pair correlation is observed to extend over some 40 atomic shells. The autocorrelation function has been calculated and compared with ferromagnets such as bcc Fe and spin-glass materials. We find no evidence in our simulations for a spin-glass behavior for any concentration of As antisites. Instead the magnetic response is better described as slow dynamics, at least when compared to that of a regular ferromagnet such as bcc Fe.
|
|
| 33. |
- Hellsvik, Johan, et al.
(författare)
-
Simulation of a spin-wave instability from atomistic spin dynamics
- 2009
-
Ingår i: Physical Review B Condensed Matter. - 0163-1829 .- 1095-3795. ; 79:18, s. 184426-
-
Tidskriftsartikel (refereegranskat)abstract
- We study the spin dynamics of a Heisenberg model at finite temperature in the presence of an external fieldor a uniaxial anisotropy. For the case of the uniaxial anisotropy, our simulations show that the macromomentpicture breaks down. An effect which we refer to as a spin-wave instability results in a nondissipative Bloch-Bloembergen-type relaxation of the macromoment where the size of the macromoment changes and can evenbe made to disappear. This relaxation mechanism is studied in detail by means of atomistic spin dynamics simulations.
|
|
| 34. |
|
|
| 35. |
- Holmström, Erik, et al.
(författare)
-
On the sharpness of the interfaces in metallic multilayers
- 2004
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 101:14, s. 4742-4745
-
Tidskriftsartikel (refereegranskat)abstract
- We show that the three most relevant magnetic properties (magnetic moment, critical temperature, and interlayer exchange coupling) of metallic multilayers can be reproduced with good accuracy by first principles theory, provided that the picture of atomically sharp interfaces is abandoned and one allows instead for both interface alloying and interface roughness. The interface of a metallic multilayer (exemplified by the Fe/V system) is demonstrated to, at best, have interdiffusion essentially over two to three atomic layers on each side of the interface. Our conclusions are the result of combining experimental work with theoretical modeling, and we argue that this approach is the best avenue to obtain accurate information about the interface quality of metallic multilayers.
|
|
| 36. |
- Holmström, Erik, et al.
(författare)
-
Structural and magnetic aspects of multilayer interfaces
- 2004
-
Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier. - 0304-8853 .- 1873-4766. ; 272-276, s. 941-
-
Tidskriftsartikel (refereegranskat)abstract
- We show that it is possible to obtain quantitative information about the interface quality by considering the magnetic moments of Fe/V multilayers. We derive a parameter space describing the quality of interfaces and argue that most of the experimentally grown samples lie within a smaller segment of this space.
|
|
| 37. |
- Lednicki, Luka, et al.
(författare)
-
Industrial IoT with Distributed Cloud Experiments using 5G LTE
- 2019
-
Ingår i: IEEE International Workshop on Factory Communication Systems - Proceedings, WFCS. - : Institute of Electrical and Electronics Engineers Inc.. - 9781728112688
-
Konferensbidrag (refereegranskat)abstract
- With the evolution of 5G it is envisioned that industrial applications with different requirements on latency and availability can be offloaded to a distributed cloud infrastructure. For example, some applications with stringent timing requirements can be hosted at the edge of the mobile network, closer to the control hardware, whereas some applications with relaxed timing requirements can be hosted in a cloud located geographically further away.This paper presents a feasibility study of hosting control applications based on OPC UA communication in a distributed cloud with LTE connectivity to the control hardware. The study includes measurements of communication round-trip time and availability of the network comparing cases where the application is hosted at a local or regional cloud. The results indicate that it is feasible to deploy industrial applications in a distributed cloud with timing requirements in the order of 100ms.
|
|
| 38. |
|
|
| 39. |
- Obeso Duque, Aleksandra, et al.
(författare)
-
A Qualitative Evaluation of Service Mesh-based Traffic Management for Mobile Edge Cloud
- 2022
-
Ingår i: 22nd IEEE/ACM International Symposium on Cluster, Cloud and Internet Computing, CCGrid 2022. - : IEEE. - 9781665499576 - 9781665499569 ; , s. 210-219
-
Konferensbidrag (refereegranskat)abstract
- Service mesh is getting widely adopted as the cloud-native mechanism for traffic management in microservice-based applications, in particular for generic IT workloads hosted in more centralized cloud environments. Performance-demanding applications continue to drive the decentralization of modern application execution environments, as in the case of mobile edge cloud. This paper presents a systematic and qualitative analysis of state-of-the-art service mesh to evaluate how suitable its design is for addressing the traffic management needs of performance-demanding application workloads hosted in a mobile edge cloud environment. With this analysis, we argue that today's dependability-centric service mesh design fails at addressing the needs of the different types of emerging mobile edge cloud workloads and motivate further research in the directions of performance-efficient architectures, stronger QoS guarantees and higher complexity abstractions of cloud-native traffic manage-ment frameworks.
|
|
| 40. |
- Obeso Duque, Aleksandra, et al.
(författare)
-
Evaluating Service Mesh-based Traffic Management for Mobile Edge Cloud
- 2022
-
Konferensbidrag (refereegranskat)abstract
- Service mesh is getting more widely adopted as the cloud-native mechanism for traffic management in microservice-based applications, in particular for generic IT workloads hosted in more centralized cloud environments. Performance-demanding applications continue to drive the decentralization of modern application execution environments as in the case of mobile edge cloud.This paper presents a systematic analysis of state-of-the-art service mesh to evaluate how suitable this approach is at addressing the traffic management needs of performance-demanding application workloads hosted in a mobile edge cloud environment. With this analysis, we argue that today’s dependability-centric service mesh fails at addressing the needs of the different types of emerging workloads in mobile edge cloud and motivate further research in the directions of performance-efficient architectures, stronger QoS guarantees and higher complexity abstractions of cloud-native traffic management frameworks.
|
|
| 41. |
|
|
| 42. |
- Rahmanian, Ali, et al.
(författare)
-
Microsplit : efficient splitting of microservices on edge clouds
- 2022
-
Ingår i: 2022 IEEE/ACM 7th Symposium on Edge Computing (SEC). - : IEEE. - 9781665486118 - 9781665486125 ; , s. 252-264
-
Konferensbidrag (refereegranskat)abstract
- Edge cloud systems reduce the latency between users and applications by offloading computations to a set of small-scale computing resources deployed at the edge of the network. However, since edge resources are constrained, they can become saturated and bottlenecked due to increased load, resulting in an exponential increase in response times or failures. In this paper, we argue that an application can be split between the edge and the cloud, allowing for better performance compared to full migration to the cloud, releasing precious resources at the edge. We model an application's internal call-Graph as a Directed-Acyclic-Graph. We use this model to develop MicroSplit, a tool for efficient splitting of microservices between constrained edge resources and large-scale distant backend clouds. MicroSplit analyzes the dependencies between the microservices of an application, and using the Louvain method for community detection---a popular algorithm from Network Science---decides how to split the microservices between the constrained edge and distant data centers. We test MicroSplit with four microservice based applications in various realistic cloud-edge settings. Our results show that Microsplit migrates up to 60% of the microservices of an application with a slight increase in the mean-response time compared to running on the edge, and a latency reduction of up to 800% compared to migrating the entire application to the cloud. Compared to other methods from the State-of-the-Art, MicroSplit reduces the total number of services on the edge by up to five times, with minimal reduction in response times.
|
|
| 43. |
- Rahmanian, Ali, et al.
(författare)
-
RAVAS: interference-aware model selection and resource allocation for live edge video analytics
- 2023
-
Ingår i: 2023 IEEE/ACM Symposium on Edge Computing (SEC). - : Institute of Electrical and Electronics Engineers (IEEE). - 9798400701238 ; , s. 27-39, s. 27-39
-
Konferensbidrag (refereegranskat)abstract
- Numerous edge applications that rely on video analytics demand precise, low-latency processing of multiple video streams from cameras. When these cameras are mobile, such as when mounted on a car or a robot, the processing load on the shared edge GPU can vary considerably. Provisioning the edge with GPUs for the worst-case load can be expensive and, for many applications, not feasible. In this paper, we introduce RAVAS, a Real-time Adaptive stream Video Analytics System that enables efficient edge GPU sharing for processing streams from various mobile cameras. RAVAS uses Q-Learning to choose between a set of Deep Neural Network (DNN) models with varying accuracy and processing requirements based on the current GPU utilization and workload. RAVAS employs an innovative resource allocation strategy to mitigate interference during concurrent GPU execution. Compared to state-of-the-art approaches, our results show that RAVAS incurs 57% less compute overhead, achieves 41% improvement in latency, and 43% savings in total GPU usage for a single video stream. Processing multiple concurrent video streams results in up to 99% and 40% reductions in latency and overall GPU usage, respectively, while meeting the accuracy constraints.
|
|
| 44. |
|
|
| 45. |
- Ranaweera, Chathurika, et al.
(författare)
-
Optical X-haul Options for 5G Fixed Wireless Access : Which One to Choose?
- 2018
-
Ingår i: IEEE INFOCOM 2018 - IEEE CONFERENCE ON COMPUTER COMMUNICATIONS WORKSHOPS (INFOCOM WKSHPS). - : IEEE. - 9781538659793
-
Konferensbidrag (refereegranskat)abstract
- 5G is anticipated to be a significant leap in the evolution of mobile communication. Being designed to facilitate 10 to 100 times more capacity than 4G, 5G is considered to be the most cost-efficient solution to provide Fixed Wireless Access (FWA)to households on a large scale where providing last mile access using wired solution might not be economically viable. With a range of promises to deliver user experience improvements, facilitating cost-efficient data transportation between FWA users and network core still remains an unsolved issue, given the enormous volume of data that will be traversing the superior 5G network. This work addresses this compelling problem by formulating a joint-optimization framework to plan and analyze the optimal deployment of diverse optical x-haul strategies that can be used in 5G-based FWA networks. The work provides a cornerstone for deployment strategies that will be imperative to realize future-proof FWA network.
|
|
| 46. |
- Raza, Muhammad Rehan, et al.
(författare)
-
Dynamic Resource Sharing for C-RANs with Joint Orchestration of Radio and Transport
- 2016
-
Ingår i: ECOC 2016 42th European Conference on Optical Communication Proceedings, September 18 - 22, 2016, Düsseldorf, Germany. - : VDE Verlag GmbH. - 9783800742745 ; , s. 1001-1003
-
Konferensbidrag (refereegranskat)abstract
- We present a resource allocation strategy for centralized radio access network architectures able to adapt to the wireless network capacity requirements. Both simulation and emulation results show that it is possible to reuse up to 33.3% of the transport resources.
|
|
| 47. |
- Rostami, Ahmad, et al.
(författare)
-
First experimental demonstration of orchestration of optical transport, RAN and cloud based on SDN
- 2015
-
Ingår i: Conference on Optical Fiber Communication, Technical Digest Series. - : Optical Society of America. - 9781557529374
-
Konferensbidrag (refereegranskat)abstract
- We design and experimentally demonstrate the first resource orchestration across DWDM optical transport, radio access networks (RANs) and cloud domains based on SDN. The orchestration enables agile service creation and optimized resource allocation.
|
|
| 48. |
- Rostami, Ahmad, et al.
(författare)
-
Orchestration of RAN and transport networks for 5G : An SDN approach
- 2017
-
Ingår i: IEEE Communications Magazine. - : Institute of Electrical and Electronics Engineers Inc.. - 0163-6804 .- 1558-1896. ; 55:4, s. 64-70
-
Tidskriftsartikel (refereegranskat)abstract
- The fifth generation of mobile networks is planned to be commercially available in a few years. The scope of 5G goes beyond introducing new radio interfaces, and will include new services like low-latency industrial applications, as well as new deployment models such as cooperative cells and densification through small cells. An efficient realization of these new features greatly benefit from tight coordination among radio and transport network resources, something that is missing in current networks. In this article, we first present an overview of the benefits and technical requirements of resource coordination across radio and transport networks in the context of 5G. Then, we discuss how SDN principles can bring programmability to both the transport and radio domains, which in turn enables the design of a hierarchical, modular, and programmable control and orchestration plane across the domains. Finally, we introduce two use cases of SDN-based transport and RAN orchestration, and present an experimental implementation of them in a testbed in our lab, which confirms the feasibility and benefits of the proposed orchestration.
|
|
| 49. |
- Saleh Sedghpour, Mohammad Reza, 1989-, et al.
(författare)
-
Hydragen : a microservice benchmark generator
- 2023
-
Ingår i: 2023 IEEE 16th international conference on cloud computing (CLOUD). - : IEEE. - 9798350304817 - 9798350304824 ; , s. 189-200
-
Konferensbidrag (refereegranskat)abstract
- Microservice-based architectures have become ubiq-uitous in large-scale software systems. Experimental cloud re-searchers constantly propose enhanced resource management mechanisms for such systems. These mechanisms need to be eval-uated using both realistic and flexible microservice benchmarks to study in which ways diverse application characteristics can affect their performance and scalability. However, current mi-croservice benchmarks have limitations including static compu-tational complexity, limited architectural scale, and fixed topology (i.e., number of tiers, fan-in, and fan-out characteristics).We therefore propose HydraGen, a tool that enables re-searchers to systematically generate benchmarks with different computational complexities and topologies, to tackle experimental evaluation of performance at scale for web-serving applications, with a focus on inter-service communication. To illustrate the potential of our open-source tool, we demonstrate how it can reproduce an existing microservice benchmark with preserved architectural properties. We also demonstrate how HydraGen can enrich the evaluation of cloud management systems based on a case study related to traffic engineering.
|
|
| 50. |
- Skubic, Björn, et al.
(författare)
-
A Comparison of Dynamic Bandwidth Allocation for EPON, GPON, and Next-Generation TDM PON
- 2009
-
Ingår i: IEEE Communications Magazine. - : IEEE Communications Society. - 0163-6804 .- 1558-1896. ; 47:3, s. S40-S48
-
Tidskriftsartikel (refereegranskat)abstract
- Dynamic bandwidth allocation in passive optical networks presents a key issue for providing efficient and fair utilization of the PON upstream bandwidth while supporting the QoS requirements of different traffic classes. In this article we compare the typical characteristics of DBA, such as bandwidth utilization, delay, and jitter at different traffic loads, within the two major standards for PONs, Ethernet PON and gigabit PON. A particular PON standard sets the framework for the operation of DBA and the limitations it faces. We illustrate these differences between EPON and GPON by means of simulations for the two standards. Moreover, we consider the evolution of both standards to their next-generation counterparts with the bit rate of 10 Gb/s and the implications to the DBA. A new simple GPON DBA algorithm is used to illustrate GPON performance. It is shown that the length of the polling cycle plays a crucial but different role for the operation of the DBA within the two standards. Moreover, only minor differences regarding DBA for current and next-generation PONs were found.
|
|
